Since TTV signals increase with observational baseline, PLATO's stare at the Kepler field will yield transit timing variations with a total baseline that includes both missions, an important opportunity unique to the PLATO mission. We discuss the regimes in period and radius where Kepler and TESS provide good samples for planet characterization, and highlight where PLATO could maximize its impact; where Kepler planets are expected to have TTV signals regardless of their prior detection, and where the TTV periodicity is comparable to or exceeds the Kepler baseline. We argue that PLATO's impact in characterizing low-mass planets with transit timing will be significantly enhanced by centering Long-duration Observation Phases on the Kepler field to ensure that 24 cameras observe Kepler targets, enabling similar transit timing precision to Kepler. Transit timing uncertainty scales as ~1/SNR. Hence, having just 6 (or 12) cameras on the Kepler field instead of 24 would increase transit timing uncertainties by ~2 (or sqrt(2)). Finally, we provide some examples of anticipated highlights from PLATO in characterizing planets with transit timing.